Definition. A metric space is a set X together with a function d (called a metric or distance function) which assigns a real number d (x, y) to every pair x, y X satisfying the properties (or axioms): 1  d (x, y) 0 and d (x, y) = 0 x = y, 2  d (x, y) = d (y, x),
Here are some facts and guidelines about formaldehyde in plywood and OSB that can help you when building a chicken coop: 1  Formaldehyde is used in the binders and resins of some manufactured wood products. 2  Offgassing can be an issue with products containing urea-formaldehyde (UF) resins.
Cost. OSB costs less than plywood and is suitable for most building construction in the form of roof and side sheathing. By comparison, a typical sheet of 1/2-inch plywood sheathing at a home center or lumberyard would be nearly double the cost of a comparable thickness of OSB.SB, or oriented strand board, is a wood product made from resin and small chips of wood called strands and sold in 4-foot by 8-foot sheets, 1/4-inch and thicker.